P. Melville, R. Mooney, and R. Nagarajan. Eighteenth National Conference on Artificial Intelligence, page 187--192. Menlo Park, CA, USA, American Association for Artificial Intelligence, (2002)
T. Sakaki, M. Okazaki, and Y. Matsuo. Proceedings of the 19th International Conference on World Wide Web, page 851--860. New York, NY, USA, ACM, (2010)
M. Atzmueller, S. Doerfel, A. Hotho, F. Mitzlaff, and G. Stumme. Modeling and Mining Ubiquitous Social Media - International Workshops MSM 2011, Boston, MA, USA, October 9, 2011, and MUSE 2011, Athens, Greece, September 5, 2011, Revised Selected Papers, volume 7472 of Lecture Notes in Computer Science, Springer Berlin Heidelberg, Heidelberg, Germany, (2012)